Cell voltage statistics MQTT/InfluxDB

[mr-manuel]

Hello,

I'm looking for a way to store all cell voltages in InfluxDB. My idea was to send the different voltages from the driver as JSON via MQTT to Node-RED, where I can create a flow to store the data in the time series database.

Has someone done this already? Is there maybe another way to get the single cell voltages without adding MQTT to the driver?

I'm using the Venus OS Large Image with Node-RED.

[Louisvdw]

All the data that the driver publish to the dbus should already be available in MQTT in Node Red.
See https://github.com/victronenergy/dbus-mqtt/blob/master/README.md if you have not yet enabled MQTT on your GX and how to read data.

The cell voltages are published at
battery.{port}/Voltages/Cell#

[mr-manuel]

Indeed it is. It works also for multiple batteries. Thanks!

N/{VRM_PORTAL_ID}/battery/{1...}/Voltages/#

[Besenreiter]

dbus-spy. I didn't know that. realy cool tool. Butr there are'nt the voltages as well:

[Besenreiter]

[mr-manuel]

As you see the driver is not providing the cell voltages. Maybe @Louisvdw can help you.

[Louisvdw]

It does seem that some Daly BMS does not publish the cell voltages the same as their protocol states. I have another report from a Daly BMS that also does not publish them.

The only real way would be to sit with an example and test what is happening. And I don't have one 😢

[Besenreiter]

But the BMS does publish the voltages, as I can see them on the same Interface when I disconnect it from the Pi (Venus) and connect to a PC and use "DalyBmsMonitorV9". There you can see the voltages. Maybe the dataformat is somehow different to the usual one?
If that would help, I can try to sniff the serial traffic and send you the log. Would that help?